1. Field of the Invention
The present invention generally relates to surgical or scalp clips and to a surgical clip applier for applying such clips to human tissue. More particulary, this invention relates to a hemostatic clip which is suitable for use as a scalp clip in the course of cranial surgery and to a surgical clip applier for repeatedly advancing scalp clips one at a time from a clip sleeve or magazine and applying the scalp clips to a tissue wound flap.
2. Description of the Prior Art
In the prior art, hemostatic clips are known for use in clamping wound flaps to prevent the flow of blood from severed blood vessels. For example, U.S. Pat. No. 3,604,425 discloses a hemostatic clip in the form of a tubular body member having a longitudinal slit extending completely across the body for receiving a wound flap when the body is distended from its original shape. A pair of outwardly extending projections is connected to the clip body at positions remote from the slit for accommodating a force applying tool. When force is applied to the outwardly extending projections, the clip body is distended from its original tubular shape to widen the slit and permit the insertion of a wound flap therein. When the force is released, the clip body returns to its original undistended tubular shape to clamp the wound flap. The clips are loaded by hand one at a time into a forceps-like tool for application to the wound flap.
The configuration of the hemostatic clip disclosed in U.S. Pat. No. 3,604,425 is unsuitable for use with a clip applying instrument in which a plurality of clips are loaded in a magazine and advanced one at a time to a set of clip actuating jaws. Because of the shape of the clip body and location of the outwardly extending projections on the clip body, it is difficult to maintain a series of such clips in alignment within a clip magazine. When the clips are arranged front to back in a row, there is a tendency of the clips to rotate relative to each other and to become misaligned. In view of these problems, it would be difficult to feed such hemostatic clips one at a time from a clip magazine and to accurately align the clips with the jaws of the clip applying instrument.
Accordingly, it is desirable to provide a surgical clip, such as a scalp clip, with a configuration which is readily operable with an applicator for applying a series of such clips to a wound flap. Also, it is desirable to provide a surgical or scalp clip with a configuration that permits a plurality of such clips to be loaded into a clip sleeve or magazine of an applicator for applying the clips to tissue. Further, it would be advantageous to provide a surgical or scalp clip with a configuration that maintains the clips in alignment when arranged front to back in a row within a clip sleeve or magazine and which prevents the clips from rotating with respect to each other in the clip sleeve or magazine. Further, it is desirable to design the surgical or scalp clip to limit the maximum separation of its clamping jaws when the clip body is distended by the applicator.
It has been proposed to provide a scalp clip applicator for applying a plurality of scalp clips one after the other without having to insert an individual scalp clip into the applicator after each application. U.S. Pat. No. 4,637,395 discloses an applicator for C-shaped scalp clips provided with a magazine for receiving a plurality of scalp clips arranged one behind the other with the free ends of one scalp clip resting against the bridge of the adjacent scalp clip. The scalp clips are urged forwardly along the magazine by a spirally wound leaf spring attached to a slider which engages the rearmost scalp clip. The frontmost clip engages the applicator jaws at the front of the magazine. Each scalp clip has laterally projecting edges to which force is applied by the applicator jaws to open the clamping jaws of the scalp clip to receive a layer of tissue. When the force is released, the clamping jaws of the scalp clip close to clamp the tissue.
In a first embodiment of the scalp clip applicator of U.S. Pat. No. 4,637,395, all clips in the magazine are advanced when the frontmost clip is released from the applicator jaws. No provision is made to retain the next scalp clip safely inside the magazine until the surgeon desires to operate the applicator to apply the next scalp clip to a tissue flap. Also, no provision is made to prevent the remaining clips in the magazine from pushing against the frontmost clip when it is actuated by the applicator jaws. As a result, the leading clip may become misaligned or accidently dislodged from the applicator jaws.
In a second embodiment of the scalp clip applicator of U.S. Pat. No. 4,637,395, a retaining nose projects downwardly into the feed path of the scalp clips to engage the second clip in the magazine. The purpose of the retaining nose is to prevent the second clip and the remaining clips from being pushed against the leading clip. However, when the lower applicator jaw is activated to open the leading clip, the retaining nose is raised so that the clips are pushed against the leading clip while it is being actuated by the applicator. As a result, the leading clip may become misaligned or dislodged from the applicator jaws. Also, in both embodiments, no provision is made to prevent the scalp clips from rotating with respect to each other so that the clips may become misaligned in the magazine.
U.S. Pat. No. 4,821,721 discloses a device for applying LeRoy-Raney clips in which a plurality of clips is loaded vertically in a magazine. The clip at the top of the magazine is driven laterally by a plunger through a tapered tunnel which forces the clip jaws open to allow the clip to be applied to a scalp edge at the end of the tunnel. However, no provision is made to maintain the scalp clips in alignment within the magazine and no provision is made to prevent the scalp clips from rotating with respect to each other in the magazine.
U.S. Pat. No. 4,674,504 discloses a clip applying device with a clip magazine including a double ratchet mechanism comprising two ratchet bars coupled to a pawl for advancing hemostatic clips through the magazine. A separate feed blade is slidably received in the magazine and used to advance the leading clip from the magazine to the applier jaws. The leading clip is moved sideways in front of the feed blade prior to its advancement to the applier jaws. The magazine is stationary and one of the ratchet bars is reciprocated by the feed blade to advance the clips from the magazine to the applier jaws.
Accordingly, it is desirable to provide a surgical clip applier including a clip sleeve or magazine in which a plurality of surgical clips is maintained in accurate alignment and the clips are advanced one at a time to a set of clip actuating jaws. Also, it is desirable to provide a surgical clip applicator which advances a plurality of surgical clips one at a time from a clip sleeve or magazine and safely retains the remaining clips within the magazine and out of engagement with the leading clip. Further, it is desirable to provide a surgical clip applicator which precludes the premature advance of another surgical or scalp clip from the clip sleeve or magazine until the application of the previous surgical clip to a tissue flap is completed.
A preferred embodiment of the surgical clip comprises a body in the form of an elongated tubular element having an ellipsoidal cross section. The surgical clip includes wound flap engaging means comprising a pair of tissue clamping jaws defined by an elongated longitudinal slit extending completely across the front of the body. The tissue clamping jaws are connected by a flexible bridge at the rear of the body whereby the body may be distended from its original tubular shape. A pair of flanges extend rearwardly from opposite sides of the body at positions remote from the longitudinal slit. The flanges are adapted to engage the jaws of an applier whereby pressure can be applied to the bridge via the flanges to widen the slit and separate the tissue clamping jaws to permit a tissue flap to be inserted therebetween. The body is resiliently urged by the bridge to maintain its original tubular shape whereby the tissue clamping jaws will engage the tissue flap when the pressure applied to the flanges by the applier is released. Jaw guide means is formed on opposite sides of the body for receiving and guiding the jaws of the applier into engagement with the flanges.
Preferably, the flanges include a pair of elongated ridges extending across the rear of the flanges for engaging the jaws of the applier. The guide means comprises a pair of indentations formed on opposite sides of the clip body which extend rearwardly into the flanges and terminate at the ridges. The indentations define a pair of recessed, flat surfaces on opposite sides of the clip body which extend rearwardly into the flanges. Each of the flat surfaces is flanked by a pair of ramp-like surfaces extending along the opposite edges of the body. The recessed, flat surfaces receive and guide the applier jaws between the ramp-like surfaces to the ridges at the rear of the flanges on the clip body.
According to another aspect of the invention, the surgical clip is provided with stop means on its rearwardly extending flanges for limiting the separation of the tissue clamping jaws when the clip body is distended by the pressure applied to the flanges. Preferably, one or more tabs is formed on the inside of each flange and the tabs on each flange are aligned with the corresponding tabs on the opposite flange. The tabs are adapted to engage each other when the body is distended to limit the maximum separation of the tissue clamping jaws. In addition, one or more notches is formed at the front of the clip body on each of the tissue clamping jaws for receiving the corresponding tabs on the flanges of another surgical clip to maintain the clips in alignment when arranged front to back in a row.
According to another aspect of the invention, the surgical clip includes shoulder means on the opposite sides of the clip body for engaging the rearwardly extending flanges of another surgical clip to maintain the clips in alignment and prevent rotation of the clips when arranged front to back in a row. Preferably, the surgical clip includes a pair of shoulders formed at the front of its tissue clamping jaws and a pair of ledges formed on the inside of its flanges. In a row of surgical clips arranged front to back, the shoulders of each surgical clip engage the ledges of another surgical clip to maintain the clips in alignment and prevent the surgical clips from rotating with respect to each other.